Dean Martin as Dr. Steve Harris

Jerry Lewis as Homer Flagg

Janet Leigh as Wally Cook

Edward Arnold as The Mayor of New York

Fred Clark as Oliver Stone

Sheree North as Jitterbug Champion

Sammy White as Waiter

Sid Tomack as Master of Ceremonies

Sig Ruman as Dr. Emile Egelhofer

Richard Loo as Dr. Lee

Raymond Greenleaf as Conductor

Walter Baldwin as Isaiah Jackson

Fay Roope as Man

Fritz Feld as Barber (uncredited)

Dabbs Greer as Scouts Leader (uncredited)

Grady Sutton as Gift Shop Clerk (uncredited)

Kathryn Grant as Manicurist (uncredited)

Bess Flowers as Patron at Wonderland Ballroom (uncredited)

Eduard Franz as Dr. Nassau (uncredited)

Marla English as Manicurist (uncredited)

Charles Fogel as City Official (uncredited)

John Alderson as Yankee Catcher (uncredited)

Art Baker as Radio Announcer (uncredited)

Frank Baker as Nightclub Patron (uncredited)

Benjie Bancroft as Cop (uncredited)

Bobby Barber as Bellboy (uncredited)

Richard Barron as Doorman (uncredited)

Don Bender as Newsboy (uncredited)

Arthur Berkeley as Waiter (uncredited)

Stanley Blystone as Ike, the Train Engineer (uncredited)

Paul Bradley as Nightclub Patron (uncredited)